Problem: One day mum asked Petya to sort his toys and get rid of some of them. Petya found a whole box of toy spiders. They were quite dear to him and the boy didn't want to throw them away. Petya conjured a cunning plan: he will glue all the spiders together and attach them to the ceiling. Besides, Petya knows that the lower the spiders will hang, the more mum is going to like it and then she won't throw his favourite toys away. Help Petya carry out the plan.

A spider consists of k beads tied together by k - 1 threads. Each thread connects two different beads, at that any pair of beads that make up a spider is either directly connected by a thread, or is connected via some chain of threads and beads.

Petya may glue spiders together directly gluing their beads. The length of each thread equals 1. The sizes of the beads can be neglected. That's why we can consider that gluing spiders happens by identifying some of the beads (see the picture). Besides, the construction resulting from the gluing process should also represent a spider, that is, it should have the given features. 

After Petya glues all spiders together, he measures the length of the resulting toy. The distance between a pair of beads is identified as the total length of the threads that connect these two beads. The length of the resulting construction is the largest distance between all pairs of beads. Petya wants to make the spider whose length is as much as possible.

<image> <image>

The picture two shows two spiders from the second sample. We can glue to the bead number 2 of the first spider the bead number 1 of the second spider. The threads in the spiders that form the sequence of threads of maximum lengths are highlighted on the picture.

Input

The first input file line contains one integer n (1 ≤ n ≤ 100) — the number of spiders. Next n lines contain the descriptions of each spider: integer ni (2 ≤ ni ≤ 100) — the number of beads, then ni - 1 pairs of numbers denoting the numbers of the beads connected by threads. The beads that make up each spider are numbered from 1 to ni.

Output

Print a single number — the length of the required construction.

Examples

Input

1
3 1 2 2 3


Output

2


Input

2
3 1 2 1 3
4 1 2 2 3 2 4


Output

4


Input

2
5 1 2 2 3 3 4 3 5
7 3 4 1 2 2 4 4 6 2 7 6 5


Output

7

Solution (in JAVA):

Solution:
import static java.lang.Math.*;
import java.util.*;
import java.io.*;

public class F {

    public void solve() throws Exception {
        
        int n = nextInt();
        int res = 0;
        
        for (int i=0; i<n; ++i) {
            int k = nextInt();
            LinkedList<Integer>[] p = new LinkedList[k+1];
            for (int j=0; j<k-1; ++j) {
                int a = nextInt(), b = nextInt();
                if (p[a]==null) p[a] = new LinkedList<Integer>();
                if (p[b]==null) p[b] = new LinkedList<Integer>();
                p[a].add(b); p[b].add(a);
            }
//          debug(p);
            int best = 0;
            for (int j=1; j<=k; ++j) {
                int len = 0;
                int[] vis = new int[k+1];
                Queue<Integer> q = new LinkedList<Integer>();
                q.add(j);
                vis[j] = 1;
                while (!q.isEmpty()) {
                    int x = q.poll();
                    for (int s: p[x]) if (vis[s]==0) {
                        q.add(s);
                        len = max(len, vis[x]);
                        vis[s] = vis[x]+1;
                    }
                }
                best = max(best,len);
//              debug(vis);
            }
            
            res += best;
        }
        
        println(res);
        
    }

    

    ////////////////////////////////////////////////////////////////////////////
    
    boolean showDebug = true;
    static boolean useFiles = !false;
    static String inFile = "input.txt";
    static String outFile = "output.txt";

    double EPS = 1e-7;
    int INF = Integer.MAX_VALUE;
    long INFL = Long.MAX_VALUE;
    double INFD = Double.MAX_VALUE;

    
    int absPos(int num) {
        return num<0 ? 0:num;
    }
    long absPos(long num) {
        return num<0 ? 0:num;
    }
    double absPos(double num) {
        return num<0 ? 0:num;
    }
    
    int min(int... nums) {
        int r = INF;
        for (int i: nums)
            if (i<r) r=i;
        return r;
    }
    int max(int... nums) {
        int r = -INF;
        for (int i: nums)
            if (i>r) r=i;
        return r;
    }
    long minL(long... nums) {
        long r = INFL;
        for (long i: nums)
            if (i<r) r=i;
        return r;
    }
    long maxL(long... nums) {
        long r = -INFL;
        for (long i: nums)
            if (i>r) r=i;
        return r;
    }
    double minD(double... nums) {
        double r = INFD;
        for (double i: nums)
            if (i<r) r=i;
        return r;
    }
    double maxD(double... nums) {
        double r = -INFD;
        for (double i: nums)
            if (i>r) r=i;
        return r;
    }
    
    long sumArr(int[] arr) {
        long res = 0;
        for (int i: arr)
            res+=i;
        return res;
    }
    long sumArr(long[] arr) {
        long res = 0;
        for (long i: arr)
            res+=i;
        return res;
    }
    double sumArr(double[] arr) {
        double res = 0;
        for (double i: arr)
            res+=i;
        return res;
    }

    long partsFitCnt(long partSize, long wholeSize) {
        return (partSize+wholeSize-1)/partSize;
    }

    boolean odd(long num) {
        return (num&1)==1;
    }
    
    boolean hasBit(int num, int pos) {
        return (num&(1<<pos))>0;
    }

    long binpow(long a, int n) {
        long r = 1;
        while (n>0) {
            if ((n&1)!=0) r*=a;
            a*=a;
            n>>=1;
        }
        return r;
    }

    boolean isLetter(char c) {
        return (c>='a' && c<='z') || (c>='A' && c<='Z');
    }
    boolean isLowercase(char c) {
        return (c>='a' && c<='z');
    }
    boolean isUppercase(char c) {
        return (c>='A' && c<='Z');
    }
    boolean isDigit(char c) {
        return (c>='0' && c<='9');
    }
    
    String stringn(String s, int n) {
        if (n<1) return "";
        StringBuilder sb = new StringBuilder(s.length()*n);
        for (int i=0; i<n; ++i) sb.append(s);
        return sb.toString();
    }
    String str(Object o) {
        return o.toString();
    }


    long timer = System.currentTimeMillis();
    void startTimer() {
        timer = System.currentTimeMillis();
    }
    void stopTimer() {
        System.err.println("time: "+(System.currentTimeMillis()-timer)/1000.0);
    }


    static class InputReader {
        private byte[] buf;
        private int bufPos = 0, bufLim = -1;
        private InputStream stream;
        public InputReader(InputStream stream, int size) {
            buf = new byte[size];
            this.stream = stream;
        }
        private void fillBuf() throws IOException {
            bufLim = stream.read(buf);
            bufPos = 0;
        }
        char read() throws IOException {
            if (bufPos>=bufLim) fillBuf(); 
            return (char)buf[bufPos++];
        }
        boolean hasInput() throws IOException {
            if (bufPos>=bufLim) fillBuf();
            return bufPos<bufLim;
        }
    }
    
    static InputReader inputReader;
    static BufferedWriter outputWriter;

    char nextChar() throws IOException {
        return inputReader.read();
    }
    char nextNonWhitespaceChar() throws IOException {
        char c = inputReader.read();
        while (c<=' ') c=inputReader.read();
        return c;
    }
    String nextWord() throws IOException {
        StringBuilder sb = new StringBuilder();
        char c = inputReader.read();
        while (c<=' ') c=inputReader.read();
        while (c>' ') {
            sb.append(c);
            c = inputReader.read();
        }
        return new String(sb);
    }
    String nextLine() throws IOException {
        StringBuilder sb = new StringBuilder();
        char c = inputReader.read();
        while (c<=' ') c=inputReader.read();
        while (c!='\n' && c!='\r') {
            sb.append(c);
            c = inputReader.read();
        }
        return new String(sb);
    }
    int nextInt() throws IOException {
        int r = 0;
        char c = nextNonWhitespaceChar();
        boolean neg = false;
        if (c=='-') neg=true;
        else r=c-48;
        c = nextChar();
        while (c>='0' && c<='9') {
            r*=10;
            r+=c-48;
            c=nextChar();
        }
        return neg ? -r:r;
    }
    long nextLong() throws IOException {
        long r = 0;
        char c = nextNonWhitespaceChar();
        boolean neg = false;
        if (c=='-') neg=true;
        else r = c-48;
        c = nextChar();
        while (c>='0' && c<='9') {
            r*=10L;
            r+=c-48L;
            c=nextChar();
        }
        return neg ? -r:r;
    }
    double nextDouble() throws NumberFormatException, IOException {
        return Double.parseDouble(nextWord());
    }
    int[] nextArr(int size) throws NumberFormatException, IOException {
        int[] arr = new int[size];
        for (int i=0; i<size; ++i)
            arr[i] = nextInt();
        return arr;
    }
    long[] nextArrL(int size) throws NumberFormatException, IOException {
        long[] arr = new long[size];
        for (int i=0; i<size; ++i)
            arr[i] = nextLong();
        return arr;
    }
    double[] nextArrD(int size) throws NumberFormatException, IOException {
        double[] arr = new double[size];
        for (int i=0; i<size; ++i)
            arr[i] = nextDouble();
        return arr;
    }
    String[] nextArrS(int size) throws NumberFormatException, IOException {
        String[] arr = new String[size];
        for (int i=0; i<size; ++i)
            arr[i] = nextWord();
        return arr;
    }
    char[] nextArrCh(int size) throws IOException {
        char[] arr = new char[size];
        for (int i=0; i<size; ++i)
            arr[i] = nextNonWhitespaceChar();
        return arr;
    }
    char[][] nextArrCh(int rows, int columns) throws IOException {
        char[][] arr = new char[rows][columns];
        for (int i=0; i<rows; ++i)
            for (int j=0; j<columns; ++j)
                arr[i][j] = nextNonWhitespaceChar();
        return arr;
    }
    char[][] nextArrChBorders(int rows, int columns, char border) throws IOException {
        char[][] arr = new char[rows+2][columns+2];
        for (int i=1; i<=rows; ++i)
            for (int j=1; j<=columns; ++j)
                arr[i][j] = nextNonWhitespaceChar();
        for (int i=0; i<columns+2; ++i) {
            arr[0][i] = border;
            arr[rows+1][i] = border;
        }
        for (int i=0; i<rows+2; ++i) {
            arr[i][0] = border;
            arr[i][columns+1] = border;
        }
        return arr;
    }

    void printf(String format, Object... args) throws IOException {
        outputWriter.write(String.format(format, args));
    }
    void print(Object o) throws IOException {
        outputWriter.write(o.toString());
    }
    void println(Object o) throws IOException {
        outputWriter.write(o.toString());
        outputWriter.newLine();
    }
    void print(Object... o) throws IOException {
        for (int i=0; i<o.length; ++i) {
            if (i!=0) outputWriter.write(' ');
            outputWriter.write(o[i].toString());
        }
    }
    void println(Object... o) throws IOException {
        print(o);
        outputWriter.newLine();
    }
    void printn(Object o, int n) throws IOException {
        String s = o.toString();
        for (int i=0; i<n; ++i) {
            outputWriter.write(s);
            if (i!=n-1) outputWriter.write(' ');
        }
    }
    void printnln(Object o, int n) throws IOException {
        printn(o, n);
        outputWriter.newLine();
    }
    void printArr(int[] arr) throws IOException {
        for (int i=0; i<arr.length; ++i) {
            if (i!=0) outputWriter.write(' ');
            outputWriter.write(Integer.toString(arr[i]));
        }
    }
    void printArr(long[] arr) throws IOException {
        for (int i=0; i<arr.length; ++i) {
            if (i!=0) outputWriter.write(' ');
            outputWriter.write(Long.toString(arr[i]));
        }
    }
    void printArr(double[] arr) throws IOException {
        for (int i=0; i<arr.length; ++i) {
            if (i!=0) outputWriter.write(' ');
            outputWriter.write(Double.toString(arr[i]));
        }
    }
    void printArr(String[] arr) throws IOException {
        for (int i=0; i<arr.length; ++i) {
            if (i!=0) outputWriter.write(' ');
            outputWriter.write(arr[i]);
        }
    }
    void printArr(char[] arr) throws IOException {
        for (char c: arr) outputWriter.write(c);
    }
    void printlnArr(int[] arr) throws IOException {
        printArr(arr);
        outputWriter.newLine();
    }
    void printlnArr(long[] arr) throws IOException {
        printArr(arr);
        outputWriter.newLine();
    }
    void printlnArr(double[] arr) throws IOException {
        printArr(arr);
        outputWriter.newLine();
    }
    void printlnArr(String[] arr) throws IOException {
        printArr(arr);
        outputWriter.newLine();
    }
    void printlnArr(char[] arr) throws IOException {
        printArr(arr);
        outputWriter.newLine();
    }
    void halt(Object... o) throws IOException {
        if (o.length!=0) println(o);
        outputWriter.flush(); outputWriter.close();
        System.exit(0);
    }
    
    void debug(Object... o) {
        if (showDebug) System.err.println(Arrays.deepToString(o));
    }


    public static void main(String[] args) throws Exception {
        Locale.setDefault(Locale.US);
        if (!useFiles) {
            inputReader = new InputReader(System.in, 1<<16);
            outputWriter = new BufferedWriter(new OutputStreamWriter(System.out), 1<<16);
        } else {
            inputReader = new InputReader(new FileInputStream(new File(inFile)), 1<<16);
            outputWriter = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(new File(outFile))), 1<<16);
        }
        new F().solve();
        outputWriter.flush(); outputWriter.close();
    }
}